1. Field of the Invention
The present invention relates to a device for controlling diffused air for an air conditioning and heating device and so on.
2. Discussion of Background
The device for controlling diffused air in a conventional air conditioning and heating device will be explained referring to FIG. 16. In FIG. 16, there is shown a vertical cross-sectional view of the indoor unit of the air conditioning and heating device disclosed in JP-B-830600. In the air conditioning and heating device, the indoor unit is constituted by a heat exchanger 1, a fan 2, an air outlet 10 for diffusing conditioned air 11, a first flap 12 for changing a diffusing angle of the conditioned air 11 in a vertical direction, and a second flap for changing a diffusing angle of the conditioned air 11 in a horizontal direction. In order to obtain required heating capacity, there are proposed a measure to ensure large air volume and a measure to heat diffused air to a high temperature (raise a refrigerant condensing temperature). In general, the latter measure is adopted to raise the temperature of diffused air since it is difficult to obtain sufficient air volume to heat a room having a large space. High temperature of diffused air is likely to rise because of increased buoyancy, creating a problem in that high temperature of air stays near to a ceiling of a room to prevent the temperature near to a floor from rising to a sufficient level and a person in the room feels uncomfortable. In a conventional way wherein high temperature of diffused air can overcome buoyancy to reach the floor so as to establish a comfortable room environment with a temperature difference minimized between the ceiling and the floor, a downward component of the velocity of the diffused air in a vertical direction has been raised to cope with the problem. For example, the case of FIG. 16 has adopted a measure to raise a downward component of the velocity of the diffused air by directing the first flap 12 substantially downwardly so that an air path defined by the first flap 12 and a lower wall surface of the air outlet 10 is convergent toward to a downstream direction.
The conventional measure stated earlier requires that a pressure generated by the fan 2 be large in order to obtain required diffused air velocity, creating a problem in that it is necessary to increase fan power. In particular, a room having a large space requires vigorous conditions for ensuring required downward component of the velocity because of increased buoyancy caused by an increase in the temperature of the diffused air in heating. On the other hand, the diffusing angle for diffused air is required to be substantially horizontal in order that heated air can reach to a position far from the air conditioning and heating device. However, conventional way has created a problem in that it is impossible to ensure required velocity in other modes than the one for diffusing conditioned air downwardly because the angle of the air outlet 10 is fixed.